DOI

10.5703/1288284313159

Abstract

This study was designed to analyze the variability associated with several test procedures used by the Indiana Department of Transportation (INDOT) in their Hot Mix Asphalt (HMA), portland cement concrete pavement (PCCP), and superstructure concrete protocols. The aim of this work was to document the variability associated with each of these test procedures toward application of this information of the development of acceptance criteria, pay factors, and pay incentives and disincentives. The studied parameters for HMA production included the air void content and VMA of the gyratory compacted mixture, in-place density, binder (asphalt) content, aggregate bulk specific gravity and water absorption, bulk specific gravity of compacted mixture, and theoretical maximum specific gravity. The analysis of existing INDOT test data and additional Purdue laboratory study indicated that testing variation was within or only slightly above the (1s) AASHTO limits for testing variation. The production variation ranged from 50 to 85% of the total variation depending on the tested parameter. The quality characteristics related to the acceptance program for PCC pavements and superstructure, which were investigated in this study, were plastic air content, flexural strength, and pavement thickness. Aggregate moisture and bulk specific gravity properties were also studied to determine what variations might be expected from a particular source. In addition to the QC/QA properties, compressive strength and split tensile strength of concrete were also studied. Based on the analysis of existing INDOT test data, it was found that all of the testing was within or only slightly above the (1s) AASHTO/ASTM testing variations. The production variation was found to range widely depending on the project. Overall, the study demonstrates that high quality testing is commonly performed in the state of Indiana and illustrates clear benefits of the technician certification programs and INDOT educational and training procedures.